1. Field of the Invention
This invention relates to a room temperature curable organopolysiloxane composition containing an aliphatic hydrocarbon, and more particularly to a room temperature curable organopolysiloxane composition that can be rapidly cured when used and is especially useful as dental impression materials or impression materials for hand prints, finger prints, external acoustic meatus, ear holes and so forth.
2. Description of the Prior Art
In conventional cases where a room temperature curable organopolysiloxane composition containing a silanol group-containing organopolysiloxane, an alkyl silicate cross-linking agent and a catalyst are used in dental impression materials or impression materials (CA 1015489 and GB 1425607, both corresponding to Japanese Pre-examination Patent Publication (kokai) 48-48753) for hand prints, finger prints, external acoustic meatus, ear holes and so forth, a paraffin type aliphatic hydrocarbon such as liquid paraffin and white vaseline is further added (Japanese Patent Publication (kokoku) 49-7579). This is added so that compositions usually separately stored in two packs can be prevented from adhering to hands when the compositions are mixed and used, and also so that the resulting cured products can be improved in release properties.
However, such a room temperature curable organopolysiloxane composition to which the paraffin type aliphatic hydrocarbon has been added in a necessary quantity has a poor storage stability. More specifically, the paraffin type aliphatic hydrocarbon tends to be oxidized during storage to change into an organic acid, an aldehyde, a hydroperoxide or the like. The organic acid and so forth thus generated causes cure retardation or insufficient curing when the composition is cured. Especially when the human body is compelled to stand still as in the case when dental impression materials are prepared or impressions of external acoustic meatus or ear holes are taken, the composition must be cured in 5 to 10 minutes. A curing time longer than that may cause problems.